Explosive



Patented Aug. ll, i942 OFFICE EXPLOSIVE Joseph D. McNutt and Samuel D.Ehrlich, New Haven, Conn, assignors to Western Cartridge Company, EastAlton, 111., a corporation of Delaware No Drawing. Application July 1,193

Serial No. 282,518

7 Claims. (Cl. 52-4) used. The double salts of lead styphnate and leadhypophosphite possess certain advantages for these purposes over many.of the compounds now employed.

Lead styphnate and basic lead styphnate are known detonators and areemployed in priming mixtures as initiators in place of mercuryfulminate. Lead hypophosphite has also been employed in priming mixturesto lower the decomposition point of priming mixtures containingdifiicultly, decomposable oxidizers. The use of lead hypophosphite inpriming mixtures is described and claimed in United States Letterspatent to Joseph D. McNutt, No. 2,136,801, granted November 15, 1938.

We have found that certain improved results can be obtained in primingmixtures and in other analogous uses when double salts of leadstyphnateand lead hypophosphite are employed'as an ingredient. These compoundsare produced from styphnic acid, sodium hydroxide, lead hypophosphiteand lead nitrate. By controlling the reaction, a compound may beproduced containing two mols. of normal lead styphnate and one 'mol. oflead hypophosphite corresponding to the chemical formula:

Crystals of this double salt are in the form of very thin hexagonalplates. Priming mixtures in which this double salt is employed are moresensitive to friction and have lower instantaneous flash point thanpriming mixtures containing a mechanical mixture of normal leadstyphnate and lead hypophosphite. The double salt of normal leadstyphnate and lead hypophosphite may be prepared as follows:

TNR 10 grs.

Adulterant 0.05 gr.

Lead nitrate 13.5 grs. .(theoretical) Sodium hydroxide 8.2 cc. (10 N.)Water 140 cc.

Lead hypophosphite 10 grs.

In forming the double salt, the trinitroresorcinate, adulterant and leadnitrate are stirred with the water at a temperature of approximately 73C. As adulterants we employ the nitro derivatives of resorufimthe nitroderivatives of indophenol and the nitro derivatives of resazurin. Saltsof these compounds may also be used, such as the lead salt ofnitroresorufin.-

Mixtures of the above materials may also be used. When carrying out areaction with the above quantities of materials, 3 grams of leadhypophosphite are then added together with all of the sodium hydroxide.This results in the formation of a temporary gel consisting of amorphousflocs and some needles. This gel breaks very quickly and normal leadstyphnate is precipitated. After seven or eight minutes the remainder ofthe lead hypophosphite is added. The hexagonal plates of the double saltof normal lead styphnate and lead hypophosphite begin to form aboutfifteen to twenty-five minutes after the addition of the remainder ofthe lead hypophosphite and the reaction is complete in about one and ahalf hours. The crystals settle quickly and the mother liquor isdecanted hot. The product is then washed with cold water a number oftimes. We have found that six washings are generally satisfactory. Fromthe above quantities of reacting materials a. yield of 22.5 grams of thedouble salt is obtained. The product is chiefly in the form of plateswith a few rods. It has an instantaneous flash point of 240 C. and adensity of 3.34.

By varying the reacting conditions and the quantities of the reactingmaterials we may also prepare a complex salt containing one mol'. eachof lead styphnate, basic lead styphnate and lead hypophosphite. Thistriple salt also is useful as an initiator and as a substitute for knownhigh explosives. It also possesses the advantage of greater sensitivityto friction and lower flash point than materials now used for thesepurposes. This compound may be prepared by employing the reactingmaterials heretofore enumerated in the quantities stated, except that 11cc. of sodium hydroxide is employed. The

yield is increased, however, if the theoretical While the methods ofpreparing the compounds set forth above are particularly advantageous inthat they produce more uniform products, either the double salt of leadstyphnate and lead hypophosphite or the salt containing one mol. each oflead styphnate, basic lead styphnate and lead hypophosphite may beprepared by other methods. For example, the double salt may be preparedfrom lead styphnate and lead hypophosphite by heating them in water to atemperature of 70 C. or it may be prepared by a reaction of sodiumhypophosphite, lead nitrate and lead styphnate. Likewise the complexbasic salt may be prepared by heating basic lead styphnate, leadstyphnate and lead hypophosphite in water. While the addition of thenitro derivatives of resorufin, the nitro derivatives of indophenol andthe nitro derivatives of resazurin, or the salts of one of thesecompounds is the preferred practice, either the double salt or thecomplex basic salt may be prepared without the use of these adulterants.

Throughout the remainder of the specification the term double salt oflead styphnate and lead hypophosphite is intended to include both thedouble salt of normal lead styphnate and lead hypophosphite and thecomplex basic salt comprising one mol. each of normal lead styphnate,basic lead styphnate and lead hypophosphite.

As stated, the new explosives may be employed in various uses in lieu ofthe explosives now used. They are particularly useful in the preparationof priming mixtures for small arms ammunition. Priming mixturescontaining this double salt; and other conventional ingredients ofpriming mixtures are more sensitive and have lower flash points thansimilar mixtures prepared with other initiators.

The following typical formulae may be employed in rim fire, center fireand shot shell ingredients may be substituted for the various oxidizersand fuels to obtain varying results necessary under differentconditions. Other explosives; such as diazodinitrophenol, normal leadstyphnate or basic lead styphnate maybe usedfor part of the double salt.Also other oxidizers. such as barium-potassium nitrate or lead peroxidemay be substituted for the oxidizers in the formulae given withoutdeparting from the spirit of the invention.

In preparing priming mixtures the ingredients are first thoroughly anduniformly mixed according to practice well known to those skilled in theart and then formed into individual pellets of the proper size forindividual charges in the customary manner. This is generally done bythe use of charge plates provided with perforations to mold pellets ofthe proper size and weight. These pellets are then transferred eitherinto priming cups for shot shell cartridges or for center fireammunition or into empty rim fire cartridge shells in the usual way. Inconnection with rim fire ammunition, the charge is forced to distributeitself in the hollow rim by spinning each shell in the customary rimfire loading machines. After the shells have been properly primed, theyare loaded with powder and shot or bullets in the usual manner.

When employed as a detonator, the double salt of lead styphnate and leadhypophosphite is loaded under suitable pressure in the usual detonatorcasing, caps or tubes and employed to detonate high explosives in thesame manner that the known initiators or detonators are employed. It maybe used to detonate any type of high explosive, such as dynamite,tetryl, trinitro toluol and other known high explosives.

We claim:

1. A priming mixture for small arms ammunition comprising the doublesalt of lead styphnate and lead hypophosphite.

2. A priming mixture for small arms ammunition comprising the doublesalt of lead styphnate and lead hypophosphite and an oxidizer.

3. A priming mixture comprising from 30 to percent of the double salt oflead styphnatelead hypophosphite, from 15 to 40 percent lead nitrate andfrom 10 to 30 percent of glass.

4. A priming mixture comprising from 20 to 50 percent of-the double saltof lead styphnatelead hypophosphite, 30 to 60 percent lead nitrate, 20to 40 percent antimony sulphide and 5 to 20 percent calcium silicide.

5. A priming mixture comprising from 15 to 40 percent of the double saltof lead styphnatelead hypophosphite, 20 to 60 percent barium nitrate, 15to 40 percent mercury fulminate, 10 to 25 percent antimony sulphide andfrom 0 to 15 priming mixtures:

Rimfire Preferred Percent percent Double sult. 30-60 50 Lead nitrate.15-40 30 Glass 10-30 20 Centerfire Preferred Percent percent Double salt20-50 35 Lead nitrate 30-60 40 Antimony sulphide. 20-40 18 Calciumsilicide. 5-20 7 Shotshell Preferred Percent n Douhlesult.... 15-40 20Barium nitrate. 20-60 35 V Fulminate mercury 15-40 25 Antimony sulphide.10-25 15 Calcium silicide 0-15 5 The above formulae are given by way ofexample and other well known priming mixture percent calcium silicide.

6. A priming mixture for small arms ammunition comprising thecompoundcontaining 2 mols. of normal lead styphnate and 1 mol. of leadhypophosphite.

7. A priming mixture for small arms ammunition comprising the compoundcontaining 1 mol. each of normal lead styphnate, basic lead styphnateand lead hypophosphite.

JOSEPH D. McNUTT. SAMUEL D. EHRLICH.

